Often there is need to match pairs of various similarly constructed components together. Examples of such matching pairs can be as simple as those used in childrens' toys or as complex as electronic components. Pairs of components such as these are often characterized as being comprised of a male and a female member. That is, one component of the pair, the male member, is interfittable into the other component of the pair, the female member. As may be appreciated, in more complex elements such as electronic components and more particularly electrical connectors, it is necessary to assure that proper keying of the components of the pair is achieved. The art, especially the electrical connector art, has seen a wide variety of techniques for matching together connectors which are to be mated to one another. These techniques include, for example, interfitting parts such as matching protrusions and recesses, corresponding indicia such as numbering or lettering, and color coding in general where pairs of connectors are uniquely color coded to provide a visual indication of mateability. Each of these keying techniques has various advantages and disadvantages.
In working with sensitive electronic components such as integrated circuits, semiconductor chips and connectors therefor, it is imperative that first, the proper components be matched with one another and second, the matched components be interconnected in the correct position. Further, as electronic assemblies using such electronic components are typically mass produced, assembly speed is essential so as to keep labor and assembly costs to a minimum. Thus any keying technique used would have to be readily identifiable so that components can be quickly matched. One example of such an assembly is where numerous electrical connectors must be matched to mating connectors supported on a printed circuit board. While speed is essential in order to minimize labor costs, there is no margin for error, as an incorrectly mated connector pair could cause significant damage to an electronic apparatus in which the pair is used. While mechanical keying elements, such as uniquely shaped protrusions and recesses, provide such fool-proof connection, they are not easily visually identifiable, thus reducing the speed at which an installer can operate. Color coding on the other hand, increases visual recognition thereby increasing the speed of installation, but color coding alone would not be absolutely fool-proof.
It can be seen that a combination of color coding and mechanical keying elements would provide increased speed and fool-proof mateability. However, if color coding is provided in a secondary manufacturing operation, it would greatly increase the cost of the components. Color coding could be embodied in the component during manufacturing thereof, such as by molding the component from a material of a particular color. However, due to mechanical and electrical constraints dictated by function and design, some electronic components must be formed from materials which cannot be color coded. Thus an installer would have to rely on the mechanical keys designed into the component without having the readily visually recognizable color to distinguish one component from another.
Accordingly, it is desirable to provide a keying technique which is easily visually identifiable to the installer and yet provides for fool-proof interconnectability of components where one or more of the components are not subject to color coding.